Curable organosilicone compositions that have good release properties are known in the art. For example, Japanese Patent Publication [Kokoku]Number Sho 47-23325 [23,325/1972] discloses a composition comprised of a of silanol-endblocked polydimethylsiloxane, an organopolysiloxane having at least 5 silicon-bonded hydrogen atoms in each molecule, and an organotin curing catalyst. In addition, U.S. Pat. No. 4,332,844 discloses a composition comprised of a polydimethylsiloxane having silicon- bonded aliphatically unsaturated groups, an organopolysi loxane having at least 2 silicon-bonded hydrogen atoms in each molecule, and a platinum group metal catalyst. With each of these compositions, the film afforded by cure under specified conditions is highly releasing and is therefore used in a wide variety of industrial sectors as a release coating.
However, these curable compositions suffer from various drawbacks in their applications as release coatings. These compositions are poorly adhesive for polyester film and polypropylene film substrates. A particular problem is that their cured films cannot be printed. As a consequence, adhesion by the cured film for the substrate has typically been improved by subjecting the fi].m substrate to a plasma treatment prior to application of the curable composition. However, this procedure is economically disadvantageous because it requires an extra process in the form of the plasma treatment. Moreover, it does not solve the problem of poor printability, and it has been necessary to accept major limitations on both concept and design.
It is an object of the present invention the introduction of a curable organosilicone composition that forms a highly releasing cured film that is strongly adhesive for such substrates as polyester film and that has good printing properties.